Conversion of 1-olefins in the presence of lead tetraacetate



Patented Mal-.14, rose OFFICE I CONVERSION OF 1-0LEF1NS IN THE PRES-ENCE F LEAD TE'IBAACETATE Francis M. Seger, Pltman, and Alexander N.

Bachanen, Woodbury, N. 1., assignorl to Socony-Vacnnm Oil Company,Incorporated, a corporation of New York No Drawing. Application am: 14,ms,

v Serial m. 44,40

9 Claims. (o1. zoo-683.15)

This invention has to do with hydrocarbon conversion and with syntheticlubricants or viscous oils prepared by such a conversion. Morespecifically. the invention is concerned with a new process forconverting certain mono-oleilnic hydrocarbons to lubricants ofoutstanding quality.

It has now been discovered that normal alpha mono-olefins having fromabout 6 to about 12 carbon atoms per molecule are converted to syntheticlubricants when in contact with lead tetraacetate at elevatedtemperatures. The synthetic lubricants so formed are characterized byhigh viscosity indices, low pour points and high stability. Thesecharacteristics are such as to make these lubricants suitable for usealone or blended with other lubricants.

As indicated above, the mono-olefins of this invention are normal orstraight chain alpha monoolefins and contain from about 6 to about 12carbon atoms. Such mono-olefins are normally liquid at temperatures ofthe order of 20-25 C. Illustrative of such mono-olefins are thefollowing: hexene-l, octene-l, decene-l, dodecene-l, and the like. Ofsuch olefins, decene-l is preferred in view of the particularlyoutstanding characteristics of the lubricants formed therefrom. It willbe clear from the foregoing examples that an alpha olefin may also bereferred to as a l-olefin.

Not only may the foregoing mono-oleflns be used individually, but theymay also be used in admixture with each other. In addition, olefinmixtures containing a substantial proportion of such mono-olefins may beused. 'Preferred of such mixtures are those'containing a majorproportion of a normal l-olefln or of normal l-olefins.

Representative of such mixtures are those obtained by the cracking ofparaflin waxes and other paraflin products, and those obtained from theFischer-Tropsch and related processes. These hydrocarbon mixtures maycontain, in addition to the normal l-olefin' or normal l-olefins, suchmaterials as: other oleflns, parailins, naphthenes and aromatics.

Lead tetra-acetate used herein to convert the foregoing normal i-olefinsto synthetic lubricants is well known, as are. methods by which it maybe prepared. One typical method of preparation, forexample, involvesreaction of lead dioxide (PbOz) and acetic anhydride. As contemplatedherein, lead tetra-acetate may be formed in situ, as from lead dioxideand acetic anhydride. 7

Conversion or the foregoing normal l-olefins in the presence of leadtetra-acetate is eflected at elevated temperatures between about 400 F.and

F. The pressure to be employed depends upon the temperature used, andordinarily a pressure suflicient to maintain the olefin in substantiallythe liquid phase is adequate. With temperatures within the 500-700" F.range, pressures of the order of 300-600 pounds per square inch aregenerally developed in the reaction vessel used. Reaction times willvary depending upon the particular olefin involved, quantity of olefin,temperature and, to a certain extent, pressure. In general, the higherthe temperature employed, the shorter the reaction time required, thecriterion used being the time required at a given reaction temperatureto eflect substantial conversion of the normal l-olefin to a viscousoil. Generally, reaction times within the range of 1 to 10 hours aresatisfactory.

With regard to proportions of olefin and lead tetra-acetate,satisfactory results may be obtained with as little as one mol of leadtetraacetate to fifty mols of a given normal l-olefin.

In such cases, however, much of the olefin is usually recoveredunreacted. Large proportions of lead tetra-acetate, however, result inwaste of this relatively expensive material without realizingcorresponding enhancement of the. desired product. Excellent results arerealized with from about 0.02 mol to about 0.4 mol of lead tetraacetateper mol of normal 1--olefin.

The process .contemplated herein is rather sim-' ply accomplished bymixing the normal l-olefin. and lead tetra-acetate in a shaker bomb typeof reactor, replacing the air therein by an inert atmosphere of nitrogenor the like, and applying the desired temperature and pressure for asuflicient length of time to complete the conversion. It will beapparent to those skilled in the art that the process may be carried outin a batch procedure such as indicated, or may be carried out in acontinuous or semi-continuous operation of the type ,widely used in thepetroleum industry.

The following detailed examples are provided for the purpose ofillustrating the process of this invention. It is to be understood,howeventhat the invention is not to be' considered as limited to I thespecific normal l-olefin shown, or the conditions or operation set forththerein.

Example I A typical conversion was accomplished as follows: A. shakerbomb was charged with 280 grams (2.0 mols) of decene-l and 44 grams (0.1mol) of lead tetraacetate. The air therein was replaced with nitrogenand the bomb heated toapproxi- 3 mately 500 F. (260 C.) for five hours.A pressure of 650 pounds per square inch developed in the bomb duringthe run.

The liquid contents of the bomb were filtered free of the relativelylarge amount of lead salt which was found to be present. A small amountof unreacted decene-l was distilled out at atmospheric pressure. Avacuum distillate cut was collected up to approximately 200 C. at 2millimeters pressure. The residual oil weighed 60 grams and had thefollowing characteristics:

Viscosity at 100 F., centistokes 44.22 Viscosity at 210 F. centistokes7.40 Viscosity at 100 F., Saybolt, secs. 204.8 Viscosity at 210 F.,Saybolt, secs 50.37 Viscosity index 132.6 Specific gravity 0.8423Gravity, A. P. I 36.5 Neutralization number (N. N.) 0.5 Saponificationnumber 4.5

Example II Decene-l was in contact with lead peroxide or dioxide (PbOa)and acetic anhydride, which most probably formed lead tetra-acetate insitu. The quantities used were: 280 grams (2.0 mols) of decene-l; 24grams (0.1 mol) of PhD: and 41 grams (0.4 mol) of acetic anhydride.

The conversion and recovery procedures were effected in the mannerdescribed in Example I, with the temperature, pressure and time,respectively: 610 F. (321 0.), 1100 pounds per square inch, and 11hours. The residual oil, 89 grams, thus obtained had the followingcharacteristics:

Viscosity at 210 F., Saybolt, secs 47.27 Viscosity index 136.1

Specific gravity 0.8348 Neutralization number (N .N.) 0.3 Bromine number12.6 Refractive index 1.4654

Pour point 30 It will be apparent that the present invention provides anefilcient and commercially feasible process for eflecting the conversionof normal l-olefins, of the character described above. This process isoi. value in the manufacture of synthetic lubricating oils, as well asin the manufacture of organic products (as the intermediate oils ofExamples I and II) important as intermediates in organic synthesis.

From the characteristics of the products produced in the illustrativeexamples above, it will be apparent that the products are highly usefulin reducing friction when placed between relatively moving parts, eitheralone or when blended with other lubricating oils. The synthetic oilsimpart desirable viscosity index (V. I.) and pour point characteristicsto the oils in combination therewith, for, as indicated above, they haveadvantageous viscosity index and pour point properties. In short, thesynthetic oils find utility in upgrading" other lubricants. Typical oilswith which the synthetic oils may be blended are mineral oils such asare normally used in internal combustion and turbine engines. When soblended, the synthetic oils may comprise the major proportion of thefinal blended oil, or may even comprise a minor proportion thereof.

One or more of the individual properties of the synthetic lubricants ofthis invention may be further improved by incorporating therewith asmall, but effective amount, of an addition agent such as a detergent,an extreme pressure agent, a foam suppressor, a viscosity index (V. I.)improver. etc. Typical detergents which may be so used are metal saltsof alkyl-substituted aromatic sulfonic or carboxylic acids, asillustrated by diwax benzene barium sulfonate and barium phenate-bariumcarboxylate of a wax-substituted phenol carboxylic acid. Extremepressure agents are well known; illustrating such materials are numerouschlorine and/or sulfur containing compositions, one such material beinga chlornaptha xanthate. Silicones, such as dimethyl silicone, may beused to illustrate foam suppressing compositions. Viscosity indeximproving agents which may be used are typified by polypropylenes,polyisobutylenes, polyacrylate esters and the like.

contemplated also as within the scope of this invention, is a method oflubricating relatively moving surfaces by maintaining therebetween afilm consisting of any of the aforesaid synthetic lubricants and blendsthereof.

It is to be understood that the foregoing description and representativeexamples are nonlimiting and serve to illustrate the invention, which isto be broadly construed in the light of the language of the appendedclaims.

We claim:

1. The process for converting a normal, alpha mono-olefin having fromsix to about twelve carbon atoms per molecule, to a viscous oilcharacterized by high viscosity index and low pour point, whichcomprises: heating said olefin with lead tetra-acetate at a temperaturebetween about 400 F. and about 700 F. for a period of time from aboutten hours to about one hour, respectively, and under a pressuresufiicient to maintain the olefin in substantially the liquid phase.

2. The process for converting a normal, alpha mono-olefin having fromsix to about twelve carbon atoms per molecule, to a viscous oilcharacterized by high viscosity index and low pour point, whichcomprises: heating said olefin with from about 0.02 mol to about 0.4 molof lead tetraacetate, per mol of said olefin, at a temperature betweenabout 400 F. and about 700 F. for a period of time from about ten hoursto about one hour, respectively, and under a pressure sufficient tomaintain the olefin in substantially the liquid phase.

3. The process for converting n-decene-l to a viscous oil characterizedby high viscosity index and low pour point, which comprises: heatingn-decene-l with from about 0.02 mol to about 0.4 mol of leadtetra-acetate, per mol of n-decene-l, at a temperature between about 400F. and about 700 F. for a period of time'from about ten hours to aboutone hour, respectively, and under a pressure sufiicient to maintain theolefin in substantially the liquid phase.

4. The process for converting n-decene-l to a viscous oil characterizedby high viscosity index and low pour point, which comprises: heating onemolar proportion of n-decene-l with about 0.05 molar proportion of leadtetra-acetate, at a temperature of about 500 F. for about five hours andunder a pressure of about 650 pounds per square inch.

5. The process for converting n-decene-l to a viscous oil characterizedby high viscosity index and low pour point, which comprises: heating onemolar proportion of n-decene-l with about 0.05 molar proportion of PhD:and with about 0.2 molar proportion of acetic anhydride, at atemperature of about 600 F. for about eleven hours and under a pressureof about 1100 pounds per square inch.

ll 6. A viscous oil characterized by high viscosity index and low pourpoint. and obtained by: heating a normal, alpha mono-olefin having fromsix to about twelve carbon atoms per molecule with lead tetra-acetate ata temperature between about 400 F. and about 700 F. for a period of timefrom about ten hours to about one hour, respectively, and under apressure sufiicient to maintain the olefin in substantially the liquidphase.

7. A viscous oil characterized by high viscosity index and low pourpoint, and obtained by: heating a normal, alpha mono-olefin having fromsix to about twelve carbon atoms per molecule with from about 0.02 molto about 0.4 mol of lead tetra-acetate, per mol of said olefin, at atemperature between about 400 F. and about 700 F. for a period of timefrom about ten hours to about one hour, respectively, and under apressure sufficient to maintain the olefin in substantially the liquidphase.

8. A viscous oil characterized by high viscosity index and low pourpoint, and obtained by: heating one molar proportion of n-decene-l withabout 0.05 molar proportion of PhD: and with about 0.2 molar proportionof acetic anhydride, at a temperature of about 600 F. for about elevenliours and under a pressure of about 100 pounds per square inch.

FRANCIS M. SEGER. ALEXANDER N. SACHANEN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,091,398 Sullivan et al. Aug.31, 1937 2,117,022 Cramer May 10, 1938 2,262,804 Jean Nov. 18, -1941FOREIGN PATENTS Number Country Date 366,112 Great Britain Jan. 25, 1932OTHER REFERENCES Hutchinson et al.: Jour. Chem. Soc. (London), vol. 69(1896), pages 212-221.

1. THE PROCESS FOR CONVERTING A NORMAL, ALPHA MONO-OLEFIN HAVING FROMSIX TO ABOUT TWELVE CARBON ATOMS PER MOLECULE, TO A VISCOUS OILCHARACTERIZED BY HIGH VISCOSITY INDEX AND LOW POUR POINT, WHICHCOMPRISES: HEATING SAID OLEFIN WITH LEAD TETRA-ACETATE AT A TEMPERATUREBETWEEN ABOUT 400*F. AND ABOUT 700*F. FOR A PERIOD OF TIME FROM ABOUTTEN HOURS TO ABOUT ONE HOUR, RESPECTIVELY, AND UNDER A PRESSURESUFFICIENT TO MAINTAIN THE OLEFIN IN SUBSTANTIALLY THE LIQUID PHASE.